camera-calibration

问题 I've used the sample OpenCV program to calculate the camera matrix and distortion coefficients from my camera and produced an xml file with the relevant data. I'm trying to use it through the undistort function but I'm not sure how to store the values as a Mat . Mat cameraMatrix; Mat distortionCoefficients; undistort(image, newImage, cameraMatrix, distortionCoefficients); I've tried: Mat cameraMatrix = 1.7514028018776246e+03 0. 1.2635000000000000e+03 0. 1.7514028018776246e+03 9

问题 Hi i am doing a project to do an image 3d reconstruction. I am the phase of calibrating the camera, which is taking a long time to do. But when i compile the code and display the checkerboard in front of the camera it goes straight to exception error unhandled. When picture not in frame, no error as soon as it gets in the frame, unhandled error occurs i don't know why. I have asked a lot of people, no body can seem to help. here is my code #include <cv.h> #include <highgui.h> #include <vector

问题 I"m using a Thermal camera for a project and I'm a little stumped so as to how to think about calculating intrinsics for it. The usual camera's would determine different points on a chessboard or something similar, but the thermal camera won't really be able to differentiate between those points. Does anyone have any insight on what the intrinsics for thermal cameras would really look like? Cheers! EDIT - In addition to the great suggestions I currently have, I'm also considering using

问题 I am trying to determine camera pose based on fiducial marker found in a scene. Fiducial: http://tinypic.com/view.php?pic=4r6k3q&s=8#.VNLnWTVVK1E Current process: Use SIFT for feature detection Use SIFT for descriptor extraction Use FLANN for matching Find the homography using CV_RANSAC Identify the corners of the fiducial Identify corners of the fiducial in the scene using perspectiveTransform() Draw lines around corners (i.e. prove that it found the fiducial in the scene Run camera

问题 I am working on a solution for calibrating a laser projector in the real world. There are a few goals for this project. 1. Take in a minimum of four points measured in the real world in 3d space that represent the projection surface. 2. Take in coordinates from the laser that are equivalent to the points received in part 1 3. Determine if the calibration file matches the real world captured points and show a deviation between the coordinate spaces 4. Using the data from the previous steps,

问题 I calibrated my mono camera using opencv. Now I know the camera intrinsic matrix and distortion coefs [K1, K2, P1 ,P2,K3 ,K4, K5, K6] of my camera. Assuming that camera is place in [x, y, z] with [Roll, Pitch, Yaw] rotations. how can I get each pixel in world coordinate when the camera is looking on the floor [z=0]. 回答1: You say that you calibrated your camera which gives you: Intrinsic parameters Extrinsic parameters (rotation, translation) Distortion coefficients First, to compensate for

问题 I am trying to get a 3x4 camera matrix for triangulation process but calibrateCamera() returns only 3x3 and 4x1 matrices. How can i get the 3x4 out of those matrices? Thanks in advance!! 回答1: calibrateCamera() returns you a 3x3 matrix as cameraMatrix, a 4x1 matrix as distCoeffs, and rvecs and tvecs that are vectors of 3x1 rotation(R) and 3x1 transformation(t) matrices. What you want is ProjectionMatrix, which is multiply [cameraMatrix] by [R|t]. Therefore, it returs you a 3x4 ProjectionMatrix

问题 Is there a free-access database containing camera calibration parameters (camera matrices, intrinsic and extrinsic parameters) for the most popular devices? I'm particularly interested in mobile-phone cameras or tablets with fixed focal length more than DSC's or DSLR's. The idea is that an app using computer vision algorithms could access the database and download the parameters and be able to work right away, instead of making the users to calibrate their devices (and avoid having to

问题 I have an application where I constantly have to undistort pixel positions to their "right" location. I tried it in Python first, thw following code yields good results: cam_m=np.array([[2590.2742, 0, 997.78192],[0, 2582.9724, 509.76907],[0, 0, 1]]) dist_c=np.array([0.088253155, 0.96952456, 0.0033740622, -0.00064934365, -6.0030732]) map1,map2=cv2.initUndistortRectifyMap(cam_m, dist_c, None, None, (1920,1024), cv2.CV_32FC1) When I tried to convert that into C++ it's just returning crap. I'm

问题 Suppose I have got the face euler angles (pitch, yaw, roll) now. How can draw the 3D Coordinate Axes which show the face pose. Here is an exmaple from here: 回答1: This can be done in pure OpenCV as long as you have your camera parameters. You should be able to create three vectors corresponding to axis x, y, z (basically points [0,0,0] [1, 0, 0], [0, 1, 0], [0, 0, 1] which you will later project into the image plane. You should first rotate those points according to your yaw/pitch/roll (e.g.